| 摘要: |
| 【目的】明确甘肃康县核桃炭疽病的病原种类及其生物学特性，为该地区核桃炭疽病的综合防治提供参考。【方法】2023年5-8月从甘肃康县核桃种植区采集具有典型症状的核桃枝干样本，采用组织分离法进行分离，并对其进行致病性测定和鉴定；利用菌丝生长速率法测定不同碳源、氮源、温度、pH值和光照对其菌丝生长和产孢量的影响。【结果】致病性测定结果表明，分离物HT14为康县核桃炭疽病的致病菌。HT14菌落形态为圆形，初期呈白色长绒毛状，4~5 d后菌落中心变为灰色且菌丝生长旺盛，形成凸起并向周围扩散，菌落边缘呈白色稀疏绒毛状，菌落背面有同心轮纹，颜色由灰色变浅后又变深；后期菌落正面呈灰色，背面灰绿色；单细胞分生孢子形态为圆柱形或卵形，孢子光滑、无色，大小为（14.43～8.29） μm×（4.71～2.61） μm。经ITS、HIS3、ACT、TUB2、CHS1和GAPDH基因序列分析，分离物HT14与松针刺盘孢（Colletotrichum fioriniae）同源性为99%，在系统发育树上聚为一支。结合形态特征将HT14菌株鉴定为松针刺盘孢，其菌丝生长和产孢的最佳碳源和氮源分别为乳糖和硝酸钠，菌丝生长最适条件为温度25 ℃、光照24 h、pH 8.0,产孢最适条件为温度25 ℃、光照24 h、pH 5.0；致死温度为52 ℃。【结论】康县核桃炭疽病致病菌为松针刺盘孢，其菌丝生长和产孢的最佳碳源为乳糖，最佳氮源为硝酸钠，菌丝生长最适条件为温度25 ℃、光照24 h、pH 8.0，产孢最适条件为温度25 ℃、光照24 h、pH 5.0。 |
| 关键词: 核桃 炭疽病 病原鉴定 松针刺盘孢 生物学特性 |
| DOI：10.13207/j.jnwafu.2026.02.012 |
| 分类号: |
| 基金项目:国家自然科学基金项目（31660148） |
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| Isolation,identification and biological characteristics of walnut anthracnose pathogen in Kang County,Gansu Province |
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TIAN Yibing, YANG Chengde, WANG Yidan, MA Ting
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Laboratory of Gansu Province Crop Disease and Pest Biological Control Engineering,College of Plant Protection,Gansu Agricultural University,Lanzhou,Gansu 730070,China
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| Abstract: |
| 【Objective】This research aims to elucidate the pathogenic species and biological characteristics of walnut anthracnose in Kang County,Gansu Province,to provide a theoretical basis for the integrated management of this disease in the region.【Method】From May to August in 2023,samples exhibiting typical symptoms were collected from walnut stems in the walnut planting region of Kang County,Gansu Province.Tissue separation method was used to isolate the samples,and their pathogenicity was subsequently determined and identified.The influence of various carbon sources,nitrogen sources,temperature,pH levels,and light conditions on mycelial growth and spore production was evaluated by the mycelial growth rate method.【Result】The pathogenicity test results confirmed that the isolate HT14 is the causative agent of walnut anthracnose in Kangxian County.The colony morphology of HT14 was round,initially white and fluffy,and after 4-5 days,the center of the colony turned gray with vigorous mycelial growth,forming raised areas that spread outward.The colony edges were white and sparse,with concentric rings on the back,whose grey color became lightened firstly and then darkened.Later,the colony front was gray and the back was gray-green.The single-celled conidia were cylindrical or oval shape,smooth,colorless,with its size being (14.43-8.29) μm× (4.71-2.61) μm.ITS, HIS3, ACT, TUB2, CHS1,and GAPDH gene sequence analysis showed that the HT14 isolate shared 99% homology with Colletotrichum fioriniae,which clustered into a single branch in the phylogenetic tree.Based on morphological characteristics,it was identified as C.fioriniae.The optimal carbon source and nitrogen source for the mycelial growth and sporulation of HT14 were determined to be lactose and sodium nitrate,respectively.The ideal conditions for mycelial growth were found to be a temperature of 25 ℃,continuous illumination of 24 h,and pH of 8.0.For sporulation,the optimal conditions were a temperature of 25 ℃,continuous illumination of 24 h,and pH of 5.0.The lethal temperature for HT14 was 52 ℃.【Conclusion】The optimal carbon source for mycelial growth and sporulation was determined to be lactose,while the optimal nitrogen source was sodium nitrate.For mycelial growth,the optimum conditions were found to be a temperature of 25 ℃,continuous illumination of 24 h,and pH of 8.0.For sporulation,the optimal conditions were a temperature of 25 ℃,continuous illumination of 24 h,and pH of 5.0. |
| Key words: Juglans regia anthracnose pathogen identification Colletotrichum fioriniae biological characteristics |
